Wayne Chrebet a football star of yesteryears and now 34 says he has bouts of depression and memory problems so severe that he cannot make the routine drive from his New Jersey home to his Long Island restaurant without a global-positioning system.
Laveranues Coles, currently with New York Jets suffered two concussions last year, but shies away from discussing the issue.
The New York Times says he was forbidden to discuss his health, his team simply does not allow players to discuss injuries.
The Jets also declined a request to speak with the doctor who oversees the care of the team's players, Elliot Pellman, himself a controversial figure in the issue.
A Jets spokesman provided a two-paragraph statement of the team's concussion treatment policy, which said, "Our approach to treating concussions is conservative." It later added, "No player has been allowed to return to a game unless he is entirely without symptoms; has normal mental status testing; and has a normal neurological examination."
But, writing in New York Times, ALAN SCHWARZ wonders whether critical decisions should be made by team-employed doctors.
The doctor who is supposed to be looking out for you is also the same guy who may put you into a game that the team has to win. You're mixing business with medicine, as Coles himself had observed once.
The league's approach to concussions could send the wrong message to young football players, it is feared.
Matt Lohr, a high school quarterback in western Pennsylvania, is one such player. He played through a concussion last year and experienced months of memory and cognitive problems that affected his schoolwork. Lohr played in a green No. 4 jersey — the same as his hero, the Packers' Brett Favre — and later admitted that doing as Mr. Favre did was his mantra: "Sure," Lohr said.
"His whole thing is playing through pain."
Even if Coles had been allowed by the Jets to speak frankly, he would most likely have other concerns. He will probably need to renegotiate his contract after this season or face a trade, and teams are wary of players with a history of concussions.
An example is Carolina Panthers linebacker Dan Morgan — who has sustained at least five concussions but was cleared to continue playing — and faced being cut had he not agreed to restructure his $2 million roster bonus into payments of $125,000 for each game he played.
Beyond acknowledging the team's concerns about subsequent concussions, the contract gave Morgan financial incentive not to reveal any concussion for treatment.
The league stated in a pamphlet that it provided to all players this season that "current research with professional athletes has not shown that having more than one or two concussions leads to permanent problems if each injury is managed properly."
Kevin Guskiewicz, chairman of the department of exercise and sport science at the University of North Carolina, and his colleagues have published several papers based on surveys of more than 2,000 former N.F.L. players that found a correlation between a player's concussion history and later-in-life clinical depression, cognitive impairment and early-onset dementia.
Guskiewicz, who presented his research at a league conference on concussions in June, said the league ignored his and other experts' findings when it published its concussion pamphlet for players, noting it did not include the research citing long-term effects.
"The first half of their statement is false," Mr. Guskiewicz said. "And the second part, if they're managed properly? What does that mean? They're just trying to raise ambiguity when the science is becoming more and more clear. The literature has proven it, we confirmed it in June in the presence of their entire committee, and I was flabbergasted that that statement showed up in their literature."
An N.F.L. spokesman, Greg Aiello, responded in a statement: "We certainly respect the work that Dr. Guskiewicz and others have done on this subject and look forward to continuing to work with him. Our medical advisers, including neurosurgeons and neurologists, do not fully share his view of the science. We are conducting research on long-term effects of concussions that we hope will help clarify this important issue."
Gene Upshaw, the executive director of the N.F.L. Players Association, is one person who had long doubted a connection between concussions and later health problems. In interviews last January and March, he contended that there was no evidence that the incidence of Alzheimer's and other dementia among former players was anything more than normal.
But by May, as reports of struggling N.F.L. retirees mounted and Mr. Guskiewicz's findings came to light, Mr. Upshaw appeared to change his mind. Speaking at a dinner at which he was honored by the Alzheimer's Association of New York, he noted that one of every five people in the audience would someday either be afflicted with Alzheimer's or be close to someone who was.
"Hopefully I won't be," he said, before attempting some humor. "But I probably will be, because I had the opportunity to play in the National Football League."
Upshaw smiled at the crowd, but they heard him only in silence.